Gales battered southwest France and northern Spain for a second day today, killing two people in Spain, cutting electricity supplies to more than one million French homes and closing roads, railways and airports, authorities said.

A falling tree killed a policeman controlling traffic in the northern Spanish province of Galicia, a police spokesman said, and in Barcelona a woman was killed on Friday when part of a wall fell on her, radio and newspapers reported.

Winds of up to 173 km an hour on the coast and 160 km an hour inland paralysed southwest France. The French weather agency Meteo France placed the region under red alert and asked residents to stay indoors for their own safety.

"Stay at home and avoid any outdoor activity. If you must go out, use extreme caution," it said in a statement.

The road traffic agency issued a list of roads and bridges blocked by fallen trees or too dangerous to use. These included the Aquitaine suspension bridge across the Garonne river at Bordeaux and bridges to the offshore islands of Re and Oleron.

The airports at Bordeaux, Biarritz, Pau and Toulouse were closed, officials said.

Spanish authorities warned people to stay away from beaches and harbours as eight-metre waves pounded the coast. The northern province of Cantabria and the Catalonia region in the northeast remained on alert because of high winds.

A liquefied natural gas tanker operated by Gaz de France, the Provalys, was in difficulties off the French coast with a technical problem making it hard to cope with the conditions, but a company spokesman said it was under control.

"The latest information is that there is no danger to people or goods," the spokesman said.

The national power grid manager, Electricite Reseau Distribution France, said nearly 1.2 million homes were cut off.

"Access to certain parts of the grid that are affected by the bad weather is particularly difficult because of fallen trees," ERDF said in a statement.

The weather drew comparisons with a huge storm in 1999 that killed 88 people in France. Then, nearly 4 million people were left without electricity and it took more than three weeks for ERDF to restore power to all clients.

"It is likely that this storm will affect a smaller geographical area than in December 1999 but it is expected to be of a similar intensity," Meteo France said.

The state railway company SNCF said it had been forced to halt services completely in the Aquitaine and Midi-Pyrenees regions, and asked travellers to postpone their journeys. It said high-speed TGV trains from Bordeaux had been stopped because of an electrical fault caused by the storm.

"Because of numerous fallen trees on the tracks, the SNCF does not expect a return to normal traffic today," it said in a statement.